Radiological findings in individuals at high risk of psychosis

Abstract

Objective: To assess the prevalence of radiological magnetic resonance imaging (MRI) findings in individuals at high risk of schizophrenia. Methods: MRI scans from individuals at high risk of schizophrenia (HR; n = 37) were assessed by a radiologist blind to group status and compared with scans from patients with first episode psychosis (FE; n = 30), depressive controls (DC; n = 17), and healthy controls (HC; n = 26).Results: There was a significantly higher proportion of radiological findings in individuals at high risk of schizophrenia (35%) and patients with first-episode psychosis (40%) than in patients with depression (18%) or healthy controls (12%). These differences were specific to findings regarded as potentially clinically significant as opposed to normal variants; however, there was no indication for medical treatment. Conclusions:The results suggest that a large proportion of those at high risk of psychosis have radiological findings on MRI scanning, and that the prevalence of radiological findings in this group is similar to that in patients with first episode psychosis. While there is an extensive literature on magnetic resonance imaging (MRI) abnormalities in psychotic disorders, most of the findings are of relatively small reductions in global and regional grey matter volume that are evident at a group level but are not detectable in an individual patient in a radiological examination. 1Nevertheless there are some abnormalities that can be detected by visual inspection, such as enlarged fluid spaces, ventricular enlargement, and cerebral atrophy.2-8 Radiological findings in first episode patients have focused mainly on cavum septi pellucidi, which is more common in this group than in controls. 9-12It is not clear as yet at what stage of the disorder these brain abnormalities occur. Neurodevelopmental models of schizophrenia propose that brain abnormalities are present before the onset of psychosis, but there is also evidence that at least some of MRI abnormalities progress over the course of the disorder. 13MRI studies of non-psychotic subjects who are at high risk of psychosis indicate that regional volumetric abnormalities comparable to those seen in schizophrenia are evident in those who are vulnerable to psychosis. Thus Lawrie et al 14 found that the relatives of patients with schizophrenia had reduced left medial temporal volume, while decreased global white and grey matter volumes were found in the nonpsychotic co-twins of patients with schizophrenia, 15 and decreased left amygdala and hippocampal volume has been described in the offspring of schizophrenic patients. 16 More recently, Pantelis et al 13 showed that individuals at high risk of psychosis who had ''prodromal'' symptoms had reduced grey matter in the right medial temporal, inferior frontal cortex, and cingulated cortex.The only radiological study in individuals at high risk of psychosis concentrated on cavum septi pellucidi and found no differences between first episode patients, relatives at high risk, and healthy volunteers.11 ...

The Effects of Antipsychotics on the Brain: What Have We Learnt from Structural Imaging of Schizophrenia? – A Systematic Review

“…People at high risk of psychosis show qualitatively similar volumetric abnormalities to patients with schizophrenia. Cortical brain abnormalities have been found in genetically defined high-risk populations such as first-degree relatives and co-twins of patients with schizophrenia, as well in people with ARMS [13,[68][69][70][71][72][73][74][75][76][77][78][79][80]. Previous longitudinal MRI studies in this group found that the subset of patients who developed psychosis showed a longitudinal reduction in GM in the orbito-frontal, temporal lobe, parietal lobe and cerebellum [79,81,82].…”

Structural neuroimaging in psychosis: a systematic review and economic evaluation

“…None were diagnostic accuracy studies and so did not report sensitivity, specificity, predictive values, likelihood ratios, diagnostic odds ratios or receiver operating characteristic curves. Some studies included one or more comparator groups 90,95,97,99,101,102,107 which took the form of a healthy control population or patients with another psychiatric diagnosis. The effectiveness of CT or MRI neuroimaging in healthy subjects or non-psychotic patients was not relevant to this review, so this information was not extracted.…”

“…Ten studies 57,87,90,94,96,98,99,[105][106][107] were designed to determine the prevalence of abnormal scan findings in a psychiatric population and appear to be cross-sectional in nature. The remaining studies sought to evaluate the use or impact of structural neuroimaging in various psychiatric populations 85,86,89,91,93,95,100,101,104 or to examine relationships between scan results and other clinical features.…”

“…88,92,97,102,103 Eighteen studies employed CT scanning for structural neuroimaging. 57,[85][86][87][88][89][91][92][93][94][95][96]100,103,104,[106][107][108] Four studies investigated MRI scans 90,97,99,105 and three studies used either CT or MRI to identify cerebral abnormalities in the patient population. 98,101,102 In all included studies (except for the review of case reports 108 ), it was intended that the patient population received either CT or MRI (or both).…”

“…None of the studies reported any follow-up over time. Eight studies were of a prospective design 85,89,90,95,97,98,102,106 and 11 studies were retrospective. 86,88,[92][93][94]96,100,101,104,105,107 Five studies employed a retrospective review of medical records in conjunction with additional prospective data collection.…”